Flail-type mower structure



June 21, 1955 c. w. MOTT FLAIL-TYPE MOWER STRUCTURE 2 Sheets-She et 1 Y Filed Nov. 30, 1953 (QIZfEENTOR.

June 21, 1955 c. w. MOTT FLAIL-TYPE MOWER STRUCTURE 2 Sheets-Sheet 2 Filed Nov. 50, 1953 INVENTOR gab .W

United State patent F This invention concernsrgrass-eutting mowers :of the character employing lzfiails swingablyrrnounted upon a rotatable carrier which when :rotating atihigh speed causes. the flails-to projectmadially therefrom to enable cutting :edges upon theirrouterends to:encounterrthe grass for cutting the same, and :relates more-iparticularly to'improvements in means for-interconnecting:the carrier and :flails.

-.The presentainventionq'relates :to mowers andimower afiails of the typewdisclosed .inmy :United States Patent 2590,065 titled --:Mower. Structure. In the patented rna- .chinef-flails of-anabortiveJ-shape are employed; in pairs with -the stems or t-shankscof: :therfiails: arranged in backto=back relation-whilenoutter vendwportions respectively thereof project divergingly from :the.:onter ends-thereof =for cutting adjacent :iminiatureswaths of grass The inner ends of the paireddlailsshanks ofathez patented machine are: pivotally connectedzwith thetcarrierforswing- .ing relativelyvthereto:"about' -'an-'axis :spaced radially from land in.- parallelism with the rotational axis" or the carrier.

Thispivoting of the flailsruponv therscarrier of v-theaprior machine enableswthe:flails'toyield "relatively: to the .car-

trier .circumferentially "thereof vupon accidentally encountering a-hard object :and ixfihllSSfiVfi wear 'and'rtear upon-the flails. :Further preservation ofthe afiails is. at-. -tnibutable'to-ihe :ability-ofrthe-paired shanks to bend into :slight divering-relation :andthus-facilitate: separation of the cutter end portions axially of the carrier andiitrans- 'versely' of their path "of revolution 1 :about :;the rotational axisv of ;the carriervand tthus' straddle narrowtimmova-ble \objects so-as toavoid/being:broken-thereby.

An object of .the :presentinvention 'is the: provision t of improved mounting-meansrof the flails' upon the car- *rier, wherein the; fiails areuniversally-pivotallya or? swingl-ably connected with the .carrier to facilitate their .dis-, H .p1acement,-without-- bending,- -when encountering -a hard yimmovable object.

A more specific object- :istthe provision .of link :means pivotally." connected with the rotatable carrier :at an inner section of such link -means :tand pivotally connected at :anaouten section thereof with 'the fiails to provide a double articulation "between the "fla'ils and the carrier and to also diminish the length of the flail shank and the mass of-the flails wherebytheyare more readily deflectible from an impenetratable'object and correspondingly less vulnerable -to 1 injury.

-Afurther object is theprovision in a'flail-type mower 'of linlc means having an' 'inner pivot section pivotally connected with'therotatable "carrier to swing-relatively to the carrier about an axis in-parallelisrn with and spaced radially from the rotational axis of the carrierand having outer bearing sections converging. radially outwardly from the carrier, together with contiguous flail V shanks imounted'respectively uponthe converging bearing sec- 2,711,067 Patented June 21,1955

."2 to centrifugal: force imposed thereon :by the mass of :the "flails during rotation 1of :thecarrierset up'react'ive'force componeiits yieldably urging the paired-flails together.

.. Afurtherfobject:is-the provision "of a novel lflail mountsiing-ilink' having a pair :offiails'swingably mounted-therei omand-such linkibeing detachably' and-:swingably mounted upon the rotatable carrier.

The above and other desirable objects inherent iii-and "encompassed: bystthe :invention are elucidated inthe en- JdGSCI iPfiQII, athepappendedclairns and the annexed ':'drawings, wherein:

" Big. laisua. .front elevational -viewof a mower -unit .con-

sstructedsaccordingto the ,principles .of the present inwention;

' L-Eig'UZis atransversesectional view taken on the line 22 of :Fig. 1;

Fig. 5 is-an enlarged partial sectional view takenon :thezline33 :ofj-Fig. :2, illustratingone ofvthe connectfing zlinksuand' the manner of its connection .-withthe car- ;rieraandawp'air of cutter flails;

:4- is :an enlarged fragmentary sectional view, taken iHEWIPIHIICCDIHHIODfiO the lines bb and dd inrFig. .3,=.showing de.tails of upper end portionsof the rflails as *zshowniid-Fig. 3 together-with vector diagrams of forces existing bet-ween the flails andthelink-upon whichthey are-xrnounted during rotation of the carrier.

Figz-S is a view :takeneimilar ly to Big. 13 but showing 'pdhevflails separated bye-a hard impenetrableobject shown in ;dotted outline;

-:Fig.- 6-is :a-n-enlarged side elevational view-of one of Fig. 7 is anedgewise elevational viewlof the flail shown "in :Fig. 6 andtaken in the direction rindicatedi'by ,the -arrows associated with the line 77 in Eig. 6.

mower unit 10in which :the present invention-is 11sef'ulis shown in Figs. -l and 2. Tlhis unit includes a ro- =itaitablecarrier casing including endtwalls I15: and 16 and :a eemiecyli-ndrical cover shroud 17 extending between'the :walls 1'51and-16and lengthwise ofthe unit. .Cover shroud 11- hasv avfront .edge 18. and a rear edge 19,.thereby pro- -viding-ian open front side of the rotor or carrierchamber -ben'eath;the edge il-8, .an open bottom side oflsuch chainmber and the open lowerportionof the reargside .of'jthe chamber beneath the rear edge 19. Adeflector wall 21,

\which is arched transversely 'extendslengthwise between :the end wallsof theunit 10 and has a front edge 22 ,-disposed-.adjacentlytothe rear edge19 of the cover shroud (and also --adjacentlyto acirculartpath traversed by the .-outer.-ends'of nails .23 during rotation ofa carrier 24 upon which 'such-rfla-ils are pivot ally or-swingably mounted.

The carriere24which is-inthe form of a shaft, having a square crosssection rotates in the direction indicated by the'arrow inEig. 2, whereby the flailsi23 are caused to cut .;;grass or the like'ofwhich the stems project upwardly tions which enable the "flails topivot universallythereon" and to separatefrom one another but which in response from a ground line 25 and sweep the cut grass stems 'in'front of the unitso that its operation wouldbe'irnpeded.

When the unit is .in'operation, it ispartly carried'by a long cylindrical groundrengaging roller 26 journalled upon a bearing rod 27 extending between the casing end walls'15Pand-1j6 whereon itismounted tat-15a, 16a. lStabilization 'of the unit upon the ground-engaging roller 26"is obtained'by means'of a stabilizer rod 28 having a lower end portion disposed within a socket 29 secured to the shroud 17 by a bracket 31. The stabilizer rod 28 is for attachment to the frame of a power driven vehicle, not shown, employed for propelling the unit and providing power for the rotation of its carrier 24.

The casing end wall supports a bearing unit 32 for journalling one end of the carrier 24 while a bearing unit 33 in the end wall 16 rotatably supports the opposite end of the carrier. The carrier projects through wall 16 and the bearing unit 33 where an end portion thereof has a pulley 34 fixed thereto for being power driven through a belt, not shown.

Carrier 24 has a plurality of apertured cars 35 projecting radially therefrom. These apertured ears 35 are arranged in four rows extending lengthwise of the carrier. Each row of ears spaced apart axially of the carrier registers with a respective corner of the square sectioned carrier; see Figs. 1 and 2. The apertured ears 35 occupy a spiral path extending in a clockwise direction (Fig. 2) about the axis a--aof the rotor, that is, the upwardly projecting ear 35 in Fig. 2 is nearest to the observer, the ear projecting rightward from the carrier is slightly farther from the observer a sufficient distance that the cutter end portions 23a of the paired flails 23 associated therewith will cut a swath slightly overlapping with the cutting end portions of the flails associated with the visible upwardly projecting car 35. The downwardly projecting ear 35 visible in Fig. 2 is slightly farther than the rightwardly projecting car from the observer a distance that the swath cut by the cutter end portions of the paired flails 23 thereon will only slightly overlap with the swath cut by the flails mounted on the rightwardly projecting car 35. The leftwardly projecting ear 35 visible in Fig. 2 is still farther from the observer axially of the carrier 24 whereby the miniature swaths cut by the cutter end portions of the paired flails 23 thereon will only slightly overlap with the swaths cut by the flails on the downwardly projecting ear 35. The upwardly projecting car 35 immediately behind the visible ear 35 in Fig. 2 is spaced endwise of the shaft 24 more distantly than the visible ear 35 projecting leftward in Fig. 2, and so on. Thus the placement of the apertured ears 35 upon the carrier 24 is such that the paired flails respectively associated therewith are in staggered relation such that the flails cut respective swaths which overlap axially of the carrier only a slight amount with the swaths upon respective opposite sides thereof cut by other flails upon the carrier.

An individual flail 23 is illustrated in Figs. 6 and 7. All flails are alike. Each flail 23 is a rigid strap-like member comprising a flat shank 23b in addition to the cutter end portion 23a which projects from the outer end 36 of such shank. An inner end 37 of the shank 23b contains an eyelet opening 38. In Fig. 7 a back side of the flail shank is designated 39 while the obverse side theerof is designated 41. Cutter end portion 230: extends angularly from the outer end portion 36 of the shank to form therewith an included angle X which is in excess of 90 degrees. Opposite edge portions 42 of the cutter end portion 23a are beveled to provide cutting edges 43.

C-links 40 constitute link means for swingably attaching each pair of the flails 23 to a respective of the apertured ears 35. Prior to inserting retainer means in the form of a cotter key 44 through a hole 45 in one end portion 46 of each C-link 40, such end portion 46 is 1 threaded through the eyelets 38 of a pair of flails disposed in back-to-back relation as illustrated in Fig. 3. These flails are slid upon the link 40 past an inner pivot or connecting section 47 having an axis b-b to an opposite or outer pivot connecting portion having an axis cc. A flattened head 48a at the opposite end of the link 40 has adiameter in excess of the eyelets 38 to prevent accidental displacement of the flails from this end of the I link. Next, each link with the pair of flails 23 disposed thereon for swinging relatively thereon about the axis c-c has its end portion 46 inserted through the hole 351! of a respective apertured ear 35 and the cotter key 44 then assembled with the opening 45 to prevent disassociation of the link from the apertured ear. Thus the apertured cars 35 constitute means pivotally connecting the inner pivot sections 47 of the link means 40 with the carrier 24 for swinging movement relatively to the carrier about respective axes b-b disposed in parallelism with the carrier axis aa. The link means 40 are so oriented by the association of their inner pivot sections 47 with the apertured ears 35 that the axis 6-0 of the outer pivot sections 48 of the linking means normally cause the paired flails 23 to swing within a plane d-d which is normal to the carrier axis and bisects the angle Y subtended by the diverging cutter end portions 23a.

Referring now to Fig. 4, the outer pivot section 48 j of the fragmentarily shown link 40 comprises contiguous bearing surfaces 49 and 49' converging radially outwardly of the carrier axis aa within a plane common to said axis and said bearing surfaces during radial outward disposition of the link means 40 attributable to centrifugal force thereof during rotation of the carrier. The radial outward centrifugal force of the leftmost flail 23 of Fig. 4 s represented by the force vector CB applied at the polnt B on the bearing surface 49. This force vector CB is divided into the vector components CA and AB. The vector force C B developed by the rightmost flail 23 in Fig. 24 is applied to the bearing surface 49' at point B to create the force components represented by the vectors C B and A B. Therefore the bearing surfaces 49 and 49' are operable by virtue of centrifugal force of the flails thereon to exert reactive force components AB and A B on such flails to impositively urge the inner ends 37 of the flail shanks into contiguity.

Although the centrifugal force acting upon the flails 23 during rotation of the carrier cooperates with the link means 40 1n creating force components pressing the paired finds in back-to-back relation, such force components are impositive in character and the flails are capable of versal movement responsively to deflecting forces of substantial magnitude imparted thereto. Should such a force be lmparted in the same sidewise direction to both of the paired flails they and the associated link 40 can pivot to a limited extent relatively to the associated apertured car 35 about an axis zz seen as a point in Fig. 3. An additional angular movement may take place for the 'flails relatively to link 40 about an axis z'z seen as a point in Fig. 3. The link therefore has universal movement to the apertured ear 35 about the perpendicular axes b-b and z-z and the flails have universal pivotal movement relative to the outer pivot section 48 of the link 40 about the axes cc and the z'z'. This non-rigidity of mount mg for the flails 23 facilitates their deflecting together or separately in any necessary direction relative to the carr er to diminish the likelihood of injury thereto by a relatively immovable hard object. Such articulated character of the flail mountings in nowise impairs the functional service of the flails since their mass is made sufficient that their mertia will maintain them in the desired orientation and paths of revolution about the carrier axis suificiently 1. In a flail-type mower, a carrier having a principal axis about which it is rotatable, a flail connecting link spaced-apart connecting sections, means pivotally connecting one of said link sections with the carrier to accommodate pivoting of the link relatively to the carrier about an axis spaced radially from the carrier structure axis and generally in parallelism therewith, a pair of rigid strap-like cutter flails each comprising a flat shank with a back face and inner and outer ends, said flail shanks being disposed with their back faces in opposed contiguous parallelism, means pivotally connecting the inner ends of the flail shanks with the link at the other of the spaced-apart connecting section thereof to accommodate pivoting of the flails relatively to the link about an axis substantially parallel with the carrier axis while the shanks are disposed in planes normal to the carrier axis, said pivotally connecting means for the inner ends of the flail shanks also accommodating pivoting of the shanks relatively to the link and to one another to assume a relation of divergence wherein their outer ends are separated axially of the carrier, and the flails also comprising respective flat outer end portions projecting from the outer ends of their shanks radially outwardly from the carrier axis at an angle of inclination with respect thereto and in diverging relation with respect to one another.

2. In a flail-type mower, a carrier having a principal axis about which it is rotatable, a cutter flail comprising a shank having inner and outer ends and a cutter end portion projecting from the outer end of the shank in diverging relation to form an included angle therewith in excess of 90 degrees, and link means disposed between the inner end of the flail shank and the carrier, said link means having inner and outer pivot sections, means pivotally connecting the inner pivot section of the link means with the carrier in radially spaced relation to its axis to accommodate pivotal swinging of the link means relatively to the carrier in a plane normal to the carrier axis, the inner end of the flail shank being pivotally connected with the outer pivot section of the link means to swing relatively thereto within a plane normal to the carrier axis and also within a plane perpendicular to such normal plane and parallel with the carrier axis, and said link means being operable through the connecting means at its inner pivot section and through the connection of its outer pivot section with the flail to normally maintain the flail so oriented that the cutter end portion is in diverging relation to the carrier axis.

3. In a flail-type mower, a carrier having a principal axis about which it is rotatable, a pair of cutter flails each comprising a shank with a back side and inner and outer ends, said flail shanks being disposed with their back sides in opposed contiguous parallelism, each flail also comprising a cutter end portion projecting angularly from the outer end of the shank thereof to form an included angle therewith in excess of 90 degrees, link means disposed between the inner ends of the flail shanks and the carrier, said link means having inner and outer pivot sections, means pivotally connecting the inner pivot section of the link means with the carrier in radially spaced relation to its axis to accommodate pivotal swinging of the link means relatively to the carrier in a plane normal to the carrier axis, the inner end of each flail shank being universally pivotally connected with the outer pivot section of the link means, said link means being operable through said link means and its inner pivot section and through the connection of its outer pivot section with the flail shanks to normally maintain the flails so oriented that their cutter end portions are in diverging relation to one another and to the carrier axis, and the universal pivotal connections of the flails with the outer pivot section of the link means facilitating swinging motion of the flails relatively to the link means within a plane normal to the carrier axis and also facilitating swinging of the flails 6 divergingly apart radially within a plane common to the carrier axis.

4. In a flail-type mower, a carrier having a principal axis about which it is rotatable, a pair of cutter flails each comprising a shank with aback side, an obverse side and inner and outer ends, said flail shanks being disposed with their back sides in opposed contiguous parallelism, each flail also comprising a cutter end portion projecting angularly from the outer end of the shank thereof to form an included angle with said obverse side in excess of degrees, link means disposed between the inner ends of the flail shanks and the carrier, said link means having an inner pivot section, means pivotally connecting the inner pivot section of the link means with the carrier in radially spaced relation to its axis to accommodate pivotal swinging of the link means relatively to the carrier within a plane normal to the carrier axis, said link means also having an outer pivot section disposed radially outwardly of the carrier axis with respect to the inner pivot section attributable to centrifugal force acting upon such link means during rotation of the carrier, said outer pivot section having contiguous bearing surfaces converging radially outwardly of the carrier axis within a plane common to such axis during such radial outward disposition of the link means, the inner ends of said flail shanks being respectively and universally pivotally mounted upon said converging pivot sections of the link means, and said converging pivot section portions being operable by virtue of centrifugal force of the flails thereon during rotation of the carrier to exert force components urging the inner ends of the flail shanks into contiguity but facilitating spreading of the outer ends of the shanks and pivotal swinging of the shanks within a plane normal to the carrier axis.

5. In a flail-type mower, a carrier having a principal axis about which it is rotatable, a pair of cutter flails each comprising a shank with a back side, an obverse side and inner and outer ends, link means having an inner pivot portion pivotally connected with the carrier to swing relatively thereto within a plane normal to the carrier axis, said link means also having an outer pivot section pivotally connected with the inner ends of the flail shanks and cooperable with centrifugal force of such flails during rotation of the carrier and consequent revolving of the link means and flails about the carrier axis to yieldably urge the flail shanks into back side to back side relation axially of the carrier, said outer pivot connection of the link means also accommodating swinging of the flails relatively thereto within said plane and swinging of said flails relatively to one another within a plane common to the carrier axis and to said shanks, and said flails also comprising cutter end portions respectively upon the outer ends of said shanks and projecting endwise outwardly therefrom in diverging rela tion to define an angle bisected by said plane.

6. In a flail assembly for use in a flail type mower, a C-link having opposite ends in opposed relation, and a pair of cutter flails, each comprising a shank with a back side, an obverse side and inner and outer ends, said shanks each having an eye opening at its inner end, the principal axes of said openings extending perpendicularly to the back and obverse sides of their associated shanks and being threaded onto the C-link with the back sides of the shanks in opposed contiguous relation to define a plane therebetween, and said flails also comprising cutter end portions respectively upon the outer ends of their shanks and projecting endwise outwardly therefrom in diverging relation at respective sides of an angle bisected by said plane.

7. The combination set forth in claim 6, wherein there is a head at one end of the C-link to prevent stripping of the flails over such end, the other end of the C-link being threadable through the flail eyelet openings, and retainer means detachably associated with such other end outwardly of the carrier and 7 .8 of the C'link to prevent accidental stripping of the flails References Cited in the file of ihis patent thereover' UNITED..STATES PATENTS 8. The combination set forth in claim 7, including an apertured stu'd for anchoring the assembly (0 'a rotary 13525-689 Baxter :Apr 31,932 carrier therefor, and said sfiid being threaded onto the 5 2175504 "Ehmann L939 2,5 80;64O :Bartch :"et. &al. V -:Jan. "1, 1952 c l k'b t th ii '1 d th t l in e Ween e S an 6 re alner means iMottt :Mar.\'18, 

